Loop antenna



April 1929- P. M. HENGSTENBERG LOOP ANTENNA Filed June 4, 1923 INVENTOR Pau/Mhenysfenbery ATTORNEY of turns of wire.

Patented Apr. 16, 1929.

UNITED STATES 1,709,666 PATENT OFFICE.

PAUL M. HENGSTENBERG, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC -80 MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

Application filed June 1,

My invention relates to antennae and particularly to the construction of loop antenna: for radio signalling. i

The object of my invention is to provide a loop antenna of simple, convenient construction and of suitable size for-efficient operation in connection with radio signalling systems, and which shall also be convenientl toldable into a compact form.

In carrying my inventlon into effect, I construct a loop antennae consistmg of a plurality of radial arms carrying a plurality The radial arms are supported by a hub to which they are lunged and in which they are held in positlon by a clamping plate. The antennre as a whole is then supported in an upright posltion by a crow-foot stand, attached to the downwardly extending radial arm.

Other objects and structural details of my invention will be apparent from the following description and claims when read 1n connection with the accompanylng drawing, wherein Fig. 1 is a view in elevation of my device.

Fig. 2 is an enlarged view of the hubs and inner ends of the radial arms of my invention, a portion of the clamping plate being broken away. I

Fig. 3 is an edge View of the hub shown in 2 from a position at right angles to that of Fig. 2.

Fig. i is a side view of the crow-foot stand shown in Fig. 1.

Fig. 5 is a view of my antenna as it appears when folded. i

Fig. 6 is an enlarged View of the hub and clamping plate, showing the manner in which the arms are loosely supported there- In all of the figures, the like reference characters refer to corresponding parts.

In the drawing, the recessed hub plate 1 and the notched clamping plate 2 form supporting, separating, and clamping elements which hold in position a number of radial arms 8. The outer extremities of the arms 3 support a series of turns of wire' l. These turns of wire may be held in place by'being passed through holes drilled in the outer ends of arms 3 or by any equivalent mechanical clamping device. The respective ends of the wire forming the turns 4 are attached to binding posts 5 and 6, which may be upon LOOP ANTENNA.

1923. Serial No. 643,170.

spacer bar 17 attached between the outer end of bar 11 and a point on extension 7 maintains a condition of perpendicularity between extension 7 and the foot structure 8, 9, 11, and 16.

\Vhen extended into the operative position illustrated in Figs. 1 and 1, the bars 8, 9 and 11 diverge radially, the angle subtended by any two of the .bars being one hundred and twenty degrees. In the folded position, the bars 8 and .9 lie against and in contact with the bar 11, on opposite sides thereof,.the bar 11 being folded up in contact with support 7 as illustrated in Fig. 5.

The hub element, shown on a larger scale in Figs. 2, 3 and 6, comprises a recessed plate 1, having a central boss through which passes a clamping bolt 12. The head 21 of the clamping bolt 12 fits into a counter-sunk opening in a clamping plate 2, provided with irregularly shaped notches 18. The plate 1 is provided with a plurality of radially cut channels 22, of suiiicient width to accommodate the ends of the arms when the loop is extended in operative position, such ends then projecting into a circular recess 23 between the outer rim of the plate 1 and the central boss 20. Each of the arms 3 is provided with an opening 241 through its inner end, and a continuous ring 25 passes through all of these openings, the arms being strung on the ring 25 in the same manner that keys are strung on the ordinary and Well known key ring. The ring 25 has no connection with either the plate 1, or the clamping plate 2, and it and the arms 3 may be entirely disassociated from the two plates by removing the wing-nut 14 and the clamping bolt 12.

As illustrated in Figs. 1 and 3, in the extended position, the arms 3 fit into the radial channels 22 of the plate 1, being prevented from radial movement by the ring, and being prevented from collapsing into the folded longer than the others, forming an extension p and the plate 1 is also rotated enough to position the tin-channeled portions thereor above the said ends. The relative position or" the plates 1, 2, the ring, and the inner ends of the arms, immediately previous to the locking operation, is shown clearly in Fig. 6.

To look the loop in the folded position, it is merely necessary to tighten the wing-nut 14, thus drawing the plates 1 and 2 toward each other, and, since the arms 3 are prevented from moving downward by the engagement of the ring 25 with the locking plate 2, consequently clamping the ends against motion.

VVhileI have shown only one embodiment of my invention in the accompanying drawing, it is capable of other changes and modifications without departing from the spirit and scope of my invention and I desire, therefore, that only such limitations shall be placed thereon as are indicated in the prior art or in the appended claims.

I claim as my invention:

1. A folding-loop antenna comprising a hub device including a circular disc member having a central recess and radial grooves, a circular clamping plate coplanar therewith and having radial slots widened at the inner ends, and a clamping bolt through the respective axes thereof, a plurality of radial arms hinged within said grooves, and a plu- 1,709,eee

rality of turns of conductor wire supported on said arms.

2. A folding loop antenna, comprising a plurality of turns of wire, a plurality olf radial arms, a plurality of attachments at the outer extremities of said arms for holding said turns of wire, a plate having recesses in which said radial arms are journalcd, a notched clamping plate for holding said arms in said recesses, a bolt extending axially through said plates and serving to hold them in operative relation and a crowfoot stand attached to the outer end. of one of said arms.

3. A foldingdoop antenna comprising a hub device including a circular disc member having a central recess and radial grooves, a circular clamping plate coplanar therewith and having radial slots widened at the inner ends and a clamping bolt through the respective axes thereof, a plurality of radial arms hinged within said grooves and a plurality of turns of conductor wire supported on said arms, said plate being adapted to rotate on said bolt, and means whereby said arms are looked into an extended position or may be folded or locked in a iolded position.

4. A ioldablo support for loop-antennm, comprising a plurality of arms, unitary means extending through one end oi each of said arms, a hub member comprising a plurality otE radially recessed discs held in parallel relation by a clamping device extending through said ui'iitary means, and means for controlling said clamping device, the recesses in said discs being so arranged that said arms may be extended and clamped in a plane parallel to said discs or may be folded and clamped perpendicularly to said (llS-.

In testimony whereof, l have hz'reunto subscribed my name this 21st day o'l. iilay, 1923.

PAUL M. I IENGSTENBERG. 

